Various devices have been proposed for preventing the unauthorized use of an electrical cord and attached plug. These devices can be categorized in five groups: (1) key locked electrical switches (see for example U.S. Pat. Nos. 1,656,586 and 3,453,402); (2) key locked electrical plugs (see for example U.S. Pat. Nos. 2,759,159; 2,761,028; 2,879,494; 3,345,603 and 3,453,402); (3) locking cover assemblies for electrical wall receptacles (see for example U.S. Pat. Nos. 2,709,198; 2,987,909; 3,096,409; 3,131,985; 3,200,989; 3,293,588 and 3,660,798;) (4) key locked electrical receptacles for appliance cord plugs (see for example U.S. Pat. Nos. 3,524,092 and 4,063,110); and (5) key locked devices for enclosing part or all of an appliance cord plug (see for example U.S. Pat. Nos. 2,643,787; 2,654,073; 2,733,416 and 2,955,272).
The electrical switch devices of the first group have the disadvantage of requiring initial fabrication as part of the appliance cord or severing of the appliance cord and subsequent installation. Such installation of the key lock switch generates increased labor costs and requires additional time compared with other devices that do not require connection directly to the appliance cord.
The devices of the second group possess the disadvantage of replacing the original plug with which the appliance was manufactured. The substitution of plugs creates increased costs, installation time, and inconvenience that would not otherwise be incurred.
The devices of the third group suffer the disadvantage of being associated with a particular stationary electrical wall receptacle and of thereby not being readily portable with one particular appliance. In addition, these inventions can not be retained on, or carried with, a particular electrical appliance's plug or cord when the appliance is not being used. Therefore such security devices, if designed to be otherwise separately portable, are very susceptible to loss or misplacement during transport of the particular electrical appliance.
The apparatus of the fourth group have the disadvantage of being cumbersome, somewhat complex, and relatively more costly as they include an electrical receptacle within a security container. Further, these devices are not as conveniently portable as may be desired owing to their typically larger mass and bulk.
The devices disclosed by the patents of the fifth group all have the disadvantage of lacking the capability to be retained on the cord or plug of the electrical appliance when the device is not being used to prevent the unauthorized use of the appliance. Therefore, such devices can be more easily lost or misplaced when the appliance is in use and the device is not performing its designated function. In addition, some of the devices disclosed by the patents of this group require the use of various springs and sliding switches to facilitate their operation (e.g., U.S. Pat. Nos. 2,654,073 and 2,733,416). Others include separable components (e.g., U.S. Pat. No. 2,643,787). The use of springs and switches and/or the use of separable multi-piece structures can increase production costs, as well as the costs associated with the marketing and servicing of such devices.
Until the present invention, the various disadvantages associated with the above-discussed types of security devices tended to make the use of such devices less convenient than desired and tended to inhibit the wide spread use of such devices.
It would be beneficial to provide an improved security device that would not have to be electrically connected to the cord or plug of the appliance. Elimination of such an installation requirement would reduce the time necessary to use the device and eliminate inconvenience associated with such installations in general.
It would also be desirable with such an improved portable security container to provide a means for attaching the container to the cord or the plug of the electrical appliance, to ensure against the loss or misplacement of the container during use or non-use of the appliance.